builtin-annotate.c

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// SPDX-License-Identifier: GPL-2.0
/*
 * builtin-annotate.c
 *
 * Builtin annotate command: Analyze the perf.data input file,
 * look up and read DSOs and symbol information and display
 * a histogram of results, along various sorting keys.
 */
#include "builtin.h"

#include "util/util.h"
#include "util/color.h"
#include <linux/list.h>
#include "util/cache.h"
#include <linux/rbtree.h>
#include "util/symbol.h"

#include "perf.h"
#include "util/debug.h"

#include "util/evlist.h"
#include "util/evsel.h"
#include "util/annotate.h"
#include "util/event.h"
#include <subcmd/parse-options.h>
#include "util/parse-events.h"
#include "util/thread.h"
#include "util/sort.h"
#include "util/hist.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/data.h"
#include "arch/common.h"
#include "util/block-range.h"

#include <dlfcn.h>
#include <errno.h>
#include <linux/bitmap.h>

struct perf_annotate {
    struct perf_tool tool;
    struct perf_session *session;
    struct annotation_options opts;
    bool       use_tui, use_stdio, use_stdio2, use_gtk;
    bool       skip_missing;
    bool       has_br_stack;
    bool       group_set;
    const char *sym_hist_filter;
    const char *cpu_list;
    DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
};

/*
 * Given one basic block:
 *
 *  from    to      branch_i
 *  * ----> *
 *      |
 *      | block
 *      v
 *      * ----> *
 *      from    to  branch_i+1
 *
 * where the horizontal are the branches and the vertical is the executed
 * block of instructions.
 *
 * We count, for each 'instruction', the number of blocks that covered it as
 * well as count the ratio each branch is taken.
 *
 * We can do this without knowing the actual instruction stream by keeping
 * track of the address ranges. We break down ranges such that there is no
 * overlap and iterate from the start until the end.
 *
 * @acme: once we parse the objdump output _before_ processing the samples,
 * we can easily fold the branch.cycles IPC bits in.
 */
static void process_basic_block(struct addr_map_symbol *start,
                struct addr_map_symbol *end,
                struct branch_flags *flags)
{
    struct symbol *sym = start->sym;
    struct annotation *notes = sym ? symbol__annotation(sym) : NULL;
    struct block_range_iter iter;
    struct block_range *entry;

    /*
     * Sanity; NULL isn't executable and the CPU cannot execute backwards
     */
    if (!start->addr || start->addr > end->addr)
        return;

    iter = block_range__create(start->addr, end->addr);
    if (!block_range_iter__valid(&iter))
        return;

    /*
     * First block in range is a branch target.
     */
    entry = block_range_iter(&iter);
    assert(entry->is_target);
    entry->entry++;

    do {
        entry = block_range_iter(&iter);

        entry->coverage++;
        entry->sym = sym;

        if (notes)
            notes->max_coverage = max(notes->max_coverage, entry->coverage);

    } while (block_range_iter__next(&iter));

    /*
     * Last block in rage is a branch.
     */
    entry = block_range_iter(&iter);
    assert(entry->is_branch);
    entry->taken++;
    if (flags->predicted)
        entry->pred++;
}

static void process_branch_stack(struct branch_stack *bs, struct addr_location *al,
                 struct perf_sample *sample)
{
    struct addr_map_symbol *prev = NULL;
    struct branch_info *bi;
    int i;

    if (!bs || !bs->nr)
        return;

    bi = sample__resolve_bstack(sample, al);
    if (!bi)
        return;

    for (i = bs->nr - 1; i >= 0; i--) {
        /*
         * XXX filter against symbol
         */
        if (prev)
            process_basic_block(prev, &bi[i].from, &bi[i].flags);
        prev = &bi[i].to;
    }

    free(bi);
}

static int hist_iter__branch_callback(struct hist_entry_iter *iter,
                      struct addr_location *al __maybe_unused,
                      bool single __maybe_unused,
                      void *arg __maybe_unused)
{
    struct hist_entry *he = iter->he;
    struct branch_info *bi;
    struct perf_sample *sample = iter->sample;
    struct perf_evsel *evsel = iter->evsel;
    int err;

    hist__account_cycles(sample->branch_stack, al, sample, false);

    bi = he->branch_info;
    err = addr_map_symbol__inc_samples(&bi->from, sample, evsel);

    if (err)
        goto out;

    err = addr_map_symbol__inc_samples(&bi->to, sample, evsel);

out:
    return err;
}

static int process_branch_callback(struct perf_evsel *evsel,
                   struct perf_sample *sample,
                   struct addr_location *al __maybe_unused,
                   struct perf_annotate *ann,
                   struct machine *machine)
{
    struct hist_entry_iter iter = {
        .evsel      = evsel,
        .sample     = sample,
        .add_entry_cb   = hist_iter__branch_callback,
        .hide_unresolved    = symbol_conf.hide_unresolved,
        .ops        = &hist_iter_branch,
    };

    struct addr_location a;
    int ret;

    if (machine__resolve(machine, &a, sample) < 0)
        return -1;

    if (a.sym == NULL)
        return 0;

    if (a.map != NULL)
        a.map->dso->hit = 1;

    ret = hist_entry_iter__add(&iter, &a, PERF_MAX_STACK_DEPTH, ann);
    return ret;
}

static bool has_annotation(struct perf_annotate *ann)
{
    return ui__has_annotation() || ann->use_stdio2;
}

static int perf_evsel__add_sample(struct perf_evsel *evsel,
                  struct perf_sample *sample,
                  struct addr_location *al,
                  struct perf_annotate *ann,
                  struct machine *machine)
{
    struct hists *hists = evsel__hists(evsel);
    struct hist_entry *he;
    int ret;

    if ((!ann->has_br_stack || !has_annotation(ann)) &&
        ann->sym_hist_filter != NULL &&
        (al->sym == NULL ||
         strcmp(ann->sym_hist_filter, al->sym->name) != 0)) {
        /* We're only interested in a symbol named sym_hist_filter */
        /*
         * FIXME: why isn't this done in the symbol_filter when loading
         * the DSO?
         */
        if (al->sym != NULL) {
            rb_erase(&al->sym->rb_node,
                 &al->map->dso->symbols);
            symbol__delete(al->sym);
            dso__reset_find_symbol_cache(al->map->dso);
        }
        return 0;
    }

    /*
     * XXX filtered samples can still have branch entires pointing into our
     * symbol and are missed.
     */
    process_branch_stack(sample->branch_stack, al, sample);

    if (ann->has_br_stack && has_annotation(ann))
        return process_branch_callback(evsel, sample, al, ann, machine);

    he = hists__add_entry(hists, al, NULL, NULL, NULL, sample, true);
    if (he == NULL)
        return -ENOMEM;

    ret = hist_entry__inc_addr_samples(he, sample, evsel, al->addr);
    hists__inc_nr_samples(hists, true);
    return ret;
}

static int process_sample_event(struct perf_tool *tool,
                union perf_event *event,
                struct perf_sample *sample,
                struct perf_evsel *evsel,
                struct machine *machine)
{
    struct perf_annotate *ann = container_of(tool, struct perf_annotate, tool);
    struct addr_location al;
    int ret = 0;

    if (machine__resolve(machine, &al, sample) < 0) {
        pr_warning("problem processing %d event, skipping it.\n",
               event->header.type);
        return -1;
    }

    if (ann->cpu_list && !test_bit(sample->cpu, ann->cpu_bitmap))
        goto out_put;

    if (!al.filtered &&
        perf_evsel__add_sample(evsel, sample, &al, ann, machine)) {
        pr_warning("problem incrementing symbol count, "
               "skipping event\n");
        ret = -1;
    }
out_put:
    addr_location__put(&al);
    return ret;
}

static int hist_entry__tty_annotate(struct hist_entry *he,
                    struct perf_evsel *evsel,
                    struct perf_annotate *ann)
{
    if (!ann->use_stdio2)
        return symbol__tty_annotate(he->ms.sym, he->ms.map, evsel, &ann->opts);

    return symbol__tty_annotate2(he->ms.sym, he->ms.map, evsel, &ann->opts);
}

static void hists__find_annotations(struct hists *hists,
                    struct perf_evsel *evsel,
                    struct perf_annotate *ann)
{
    struct rb_node *nd = rb_first(&hists->entries), *next;
    int key = K_RIGHT;

    while (nd) {
        struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);
        struct annotation *notes;

        if (he->ms.sym == NULL || he->ms.map->dso->annotate_warned)
            goto find_next;

        if (ann->sym_hist_filter &&
            (strcmp(he->ms.sym->name, ann->sym_hist_filter) != 0))
            goto find_next;

        notes = symbol__annotation(he->ms.sym);
        if (notes->src == NULL) {
find_next:
            if (key == K_LEFT)
                nd = rb_prev(nd);
            else
                nd = rb_next(nd);
            continue;
        }

        if (use_browser == 2) {
            int ret;
            int (*annotate)(struct hist_entry *he,
                    struct perf_evsel *evsel,
                    struct hist_browser_timer *hbt);

            annotate = dlsym(perf_gtk_handle,
                     "hist_entry__gtk_annotate");
            if (annotate == NULL) {
                ui__error("GTK browser not found!\n");
                return;
            }

            ret = annotate(he, evsel, NULL);
            if (!ret || !ann->skip_missing)
                return;

            /* skip missing symbols */
            nd = rb_next(nd);
        } else if (use_browser == 1) {
            key = hist_entry__tui_annotate(he, evsel, NULL, &ann->opts);

            switch (key) {
            case -1:
                if (!ann->skip_missing)
                    return;
                /* fall through */
            case K_RIGHT:
                next = rb_next(nd);
                break;
            case K_LEFT:
                next = rb_prev(nd);
                break;
            default:
                return;
            }

            if (next != NULL)
                nd = next;
        } else {
            hist_entry__tty_annotate(he, evsel, ann);
            nd = rb_next(nd);
            /*
             * Since we have a hist_entry per IP for the same
             * symbol, free he->ms.sym->src to signal we already
             * processed this symbol.
             */
            zfree(&notes->src->cycles_hist);
            zfree(&notes->src);
        }
    }
}

static int __cmd_annotate(struct perf_annotate *ann)
{
    int ret;
    struct perf_session *session = ann->session;
    struct perf_evsel *pos;
    u64 total_nr_samples;

    if (ann->cpu_list) {
        ret = perf_session__cpu_bitmap(session, ann->cpu_list,
                           ann->cpu_bitmap);
        if (ret)
            goto out;
    }

    if (!ann->opts.objdump_path) {
        ret = perf_env__lookup_objdump(&session->header.env,
                           &ann->opts.objdump_path);
        if (ret)
            goto out;
    }

    ret = perf_session__process_events(session);
    if (ret)
        goto out;

    if (dump_trace) {
        perf_session__fprintf_nr_events(session, stdout);
        perf_evlist__fprintf_nr_events(session->evlist, stdout);
        goto out;
    }

    if (verbose > 3)
        perf_session__fprintf(session, stdout);

    if (verbose > 2)
        perf_session__fprintf_dsos(session, stdout);

    total_nr_samples = 0;
    evlist__for_each_entry(session->evlist, pos) {
        struct hists *hists = evsel__hists(pos);
        u32 nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];

        if (nr_samples > 0) {
            total_nr_samples += nr_samples;
            hists__collapse_resort(hists, NULL);
            /* Don't sort callchain */
            perf_evsel__reset_sample_bit(pos, CALLCHAIN);
            perf_evsel__output_resort(pos, NULL);

            if (symbol_conf.event_group &&
                !perf_evsel__is_group_leader(pos))
                continue;

            hists__find_annotations(hists, pos, ann);
        }
    }

    if (total_nr_samples == 0) {
        ui__error("The %s file has no samples!\n", session->data->file.path);
        goto out;
    }

    if (use_browser == 2) {
        void (*show_annotations)(void);

        show_annotations = dlsym(perf_gtk_handle,
                     "perf_gtk__show_annotations");
        if (show_annotations == NULL) {
            ui__error("GTK browser not found!\n");
            goto out;
        }
        show_annotations();
    }

out:
    return ret;
}

static const char * const annotate_usage[] = {
    "perf annotate [<options>]",
    NULL
};

int cmd_annotate(int argc, const char **argv)
{
    struct perf_annotate annotate = {
        .tool = {
            .sample = process_sample_event,
            .mmap   = perf_event__process_mmap,
            .mmap2  = perf_event__process_mmap2,
            .comm   = perf_event__process_comm,
            .exit   = perf_event__process_exit,
            .fork   = perf_event__process_fork,
            .namespaces = perf_event__process_namespaces,
            .attr   = perf_event__process_attr,
            .build_id = perf_event__process_build_id,
            .tracing_data   = perf_event__process_tracing_data,
            .feature    = perf_event__process_feature,
            .ordered_events = true,
            .ordering_requires_timestamps = true,
        },
        .opts = annotation__default_options,
    };
    struct perf_data data = {
        .mode  = PERF_DATA_MODE_READ,
    };
    struct option options[] = {
    OPT_STRING('i', "input", &input_name, "file",
            "input file name"),
    OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
           "only consider symbols in these dsos"),
    OPT_STRING('s', "symbol", &annotate.sym_hist_filter, "symbol",
            "symbol to annotate"),
    OPT_BOOLEAN('f', "force", &data.force, "don't complain, do it"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_BOOLEAN('q', "quiet", &quiet, "do now show any message"),
    OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
            "dump raw trace in ASCII"),
    OPT_BOOLEAN(0, "gtk", &annotate.use_gtk, "Use the GTK interface"),
    OPT_BOOLEAN(0, "tui", &annotate.use_tui, "Use the TUI interface"),
    OPT_BOOLEAN(0, "stdio", &annotate.use_stdio, "Use the stdio interface"),
    OPT_BOOLEAN(0, "stdio2", &annotate.use_stdio2, "Use the stdio interface"),
    OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
                    "don't load vmlinux even if found"),
    OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
           "file", "vmlinux pathname"),
    OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
            "load module symbols - WARNING: use only with -k and LIVE kernel"),
    OPT_BOOLEAN('l', "print-line", &annotate.opts.print_lines,
            "print matching source lines (may be slow)"),
    OPT_BOOLEAN('P', "full-paths", &annotate.opts.full_path,
            "Don't shorten the displayed pathnames"),
    OPT_BOOLEAN(0, "skip-missing", &annotate.skip_missing,
            "Skip symbols that cannot be annotated"),
    OPT_BOOLEAN_SET(0, "group", &symbol_conf.event_group,
            &annotate.group_set,
            "Show event group information together"),
    OPT_STRING('C', "cpu", &annotate.cpu_list, "cpu", "list of cpus to profile"),
    OPT_CALLBACK(0, "symfs", NULL, "directory",
             "Look for files with symbols relative to this directory",
             symbol__config_symfs),
    OPT_BOOLEAN(0, "source", &annotate.opts.annotate_src,
            "Interleave source code with assembly code (default)"),
    OPT_BOOLEAN(0, "asm-raw", &annotate.opts.show_asm_raw,
            "Display raw encoding of assembly instructions (default)"),
    OPT_STRING('M', "disassembler-style", &annotate.opts.disassembler_style, "disassembler style",
           "Specify disassembler style (e.g. -M intel for intel syntax)"),
    OPT_STRING(0, "objdump", &annotate.opts.objdump_path, "path",
           "objdump binary to use for disassembly and annotations"),
    OPT_BOOLEAN(0, "group", &symbol_conf.event_group,
            "Show event group information together"),
    OPT_BOOLEAN(0, "show-total-period", &symbol_conf.show_total_period,
            "Show a column with the sum of periods"),
    OPT_BOOLEAN('n', "show-nr-samples", &symbol_conf.show_nr_samples,
            "Show a column with the number of samples"),
    OPT_CALLBACK_DEFAULT(0, "stdio-color", NULL, "mode",
                 "'always' (default), 'never' or 'auto' only applicable to --stdio mode",
                 stdio__config_color, "always"),
    OPT_END()
    };
    int ret;

    set_option_flag(options, 0, "show-total-period", PARSE_OPT_EXCLUSIVE);
    set_option_flag(options, 0, "show-nr-samples", PARSE_OPT_EXCLUSIVE);


    ret = hists__init();
    if (ret < 0)
        return ret;

    argc = parse_options(argc, argv, options, annotate_usage, 0);
    if (argc) {
        /*
         * Special case: if there's an argument left then assume that
         * it's a symbol filter:
         */
        if (argc > 1)
            usage_with_options(annotate_usage, options);

        annotate.sym_hist_filter = argv[0];
    }

    if (symbol_conf.show_nr_samples && annotate.use_gtk) {
        pr_err("--show-nr-samples is not available in --gtk mode at this time\n");
        return ret;
    }

    if (quiet)
        perf_quiet_option();

    data.file.path = input_name;

    annotate.session = perf_session__new(&data, false, &annotate.tool);
    if (annotate.session == NULL)
        return -1;

    annotate.has_br_stack = perf_header__has_feat(&annotate.session->header,
                              HEADER_BRANCH_STACK);

    if (annotate.group_set)
        perf_evlist__force_leader(annotate.session->evlist);

    ret = symbol__annotation_init();
    if (ret < 0)
        goto out_delete;

    annotation_config__init();

    symbol_conf.try_vmlinux_path = true;

    ret = symbol__init(&annotate.session->header.env);
    if (ret < 0)
        goto out_delete;

    if (annotate.use_stdio || annotate.use_stdio2)
        use_browser = 0;
    else if (annotate.use_tui)
        use_browser = 1;
    else if (annotate.use_gtk)
        use_browser = 2;

    setup_browser(true);

    if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
        sort__mode = SORT_MODE__BRANCH;
        if (setup_sorting(annotate.session->evlist) < 0)
            usage_with_options(annotate_usage, options);
    } else {
        if (setup_sorting(NULL) < 0)
            usage_with_options(annotate_usage, options);
    }

    ret = __cmd_annotate(&annotate);

out_delete:
    /*
     * Speed up the exit process, for large files this can
     * take quite a while.
     *
     * XXX Enable this when using valgrind or if we ever
     * librarize this command.
     *
     * Also experiment with obstacks to see how much speed
     * up we'll get here.
     *
     * perf_session__delete(session);
     */
    return ret;
}